Biology

chapter 1
WHAT IS BIOLOGY?
it is the scientific study of living things and their interactions with the environment
→what is the cause of increasing autism prevalence

correlation does not imply causation

WHY STUDY BIOLOGY

this course is designed to give students an understanding of and appreciation for, the
“science of life” and apply that knowledge to the evaluation of current issues
think of a living organism

what makes it alive?

six characteristics

cells

organization

Biology 1
 energy use

homeostasis

reproduction, growth and development

evolution
WHAT MAKES SOMETHING ALIVE
all living things are made of one or more cells
→ organization

Biology 2
 → energy use

organisms can convert energy

Biology 3
 → maintains homeostasis

→ organisms grow, develop and reproduce

material passed from one to the next

✨evolution✨
→organisms have adaptations that help them survive and reproduce in their habitat

Biology 4
 populations of organisms changes over time

TREE OF LIFE INCLUDES THREE MAIN BRANCHES

Biology 5
 → taxonomy

is the scientific study of naming and classifying organisms

→ domain bacteria and domain archaea are prokaryotic and unicellular

DOMAIN EUKARYA: 4 KINGDOMS

(for the most part they are split on how they “get food”)

→ kingdom plantae (plants)

produce their own food

→kingdom fungi (mushrooms)

decompose their food: external digestion and absorption

→kingdom animalia (animals)

ingest their food

→protists

multiple kingdoms: some produce, some consume, some decompose

WHAT IS SCIENCE

the word science is derived from a Latin verb meaning “to know”

a process used to solve problems and to understand natural events

involves the scientific method

Biology 6
 CONSTRUCTING HYPOTHESES
hypothesis

a tentative explanation that a scientist proposes for a specific phenomenon that has
been observed
TYPES OF SCIENCE

discovery science
verifiable observations and measurements are the data of discovery science
controlled experiments

prediction
what you expect to observe in your experiment

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 includes

independent variable (manipulated)

depended variable (measured)

controls (constants)
THEORY

a theory may be defined as a widely accepted, plausible, general statement about a

fundamental concept about nature

broader and more comprehensive in scope than hypotheses

become widely accepted only after they are supported by an accumulation of

extensive evidence

can still be tested and modified

LIMITATIONS OF SCIENCE

the scientific method can only be applied to questions that have a factual base

questions of morality, values, social issues and attitudes cannot be tested

scientifically

science knowledge is self-correcting.

chapter 2
the chemistry of life

→some basic chemistry

zoom in close enough to anything, and you will end up at the chemical level
→matter: elements and compounds

→→matter is anything that occupies space and has mass

matter is found on earth in three physical states:

solid, liquid and gas

→→matter is composed of chemical elements

elements are substances that cannot be broken down into other substances by
chemical means

Biology 8
 there are 92 naturally occurring elements on earth

→→twenty five are essential to life

four of these make up about 96% of the weight of the human body
(Oxygen 65%)

(Carbon 18.5%)
(Hydrogen 9.5%)

(Nitrogen 3.3%)
→atoms
each element consists of one kind of atom

-an atom is the smallest unit of matter that still retains the properties of an element
→structure of atoms
atoms are composed of subatomic particles

proton is pos charged (located in the nucleus)

neutron is electrically charged (located in the nucleus)

electron is neg charged (orbit around the nucleus)

→periodic table of elements

the periodic table lists all of the known elements
(we been knew bc of chemistry, but this is a college bio class so I guess that chem
plays a role here too)
key to the periodic table

elements are organized on the table according to their atomic number, usually
found near the top of the square

the atomic number refers to how many protons an atom of that element has

for instance, hydrogen has 1 proton, so it’s atomic number is one

the atomic number is unique to that element. no two elements have the same
number

electron arrangement and the chemical properties of atoms

Biology 9
 electrons orbit the nucleus of an atom in specific electron shells

the number of electrons in the outer most shell determines the chemical
properties of an atom

electron shells

energy levels hold specific numbers of electrons

the first energy level van hold 2 electrons
the other energy levels can hold 8 electrons

isotopes
an alternate mass forms of an element

same number of protons and electrons but a different number of neutrons

can be stable or radioactive

radioactive isotopes

exposure to radioactive isotopes can damage DNA

1986 Chernobyl nuclear accident

PET scans

diagnose Alzheimer's disease before onset of symptoms

chemical bonding and molecules

chemical reactions enable atoms to give up or acquire electrons in order to

complete their outer shells

molecule

two or more atoms joined by a chemical bond

compound

substances that contain two or more elements in a fixed ratio

chemical bonds link atoms

atoms are organized into molecules

valence electrons determine bonding

Biology 10
 the number and distribution of electrons around an atom determines
whether atoms react with one another
chemical bonding and molecules

→Covalent
when atoms share electrons, as in this methane molecule, covalent bonds are formed

→electronegativity
is a measure of an atom’s ability to attract electrons

→determines if bonds are polar or nonpolar

→some atoms have such different electronegativities that one atom
completely pulls stronger than the other atom or pulls an electron completely
from the other

→Polar

chapter 3
cell theory

1. all organisms are composed of cells

2. cells are the smallest unit of life

3. cells arise only from pre-existing cells

discovered in 1665 by robert hooke

Biology 11
 called the structures “cells

basic cell structure

all cells have four structures in common

1. plasma membrane

2. cytoplasm

3. genetic material

4. ribosomes

plasma membrane

a phaspholipid has two regions

hydrophilic head

hydrophobic tails

Biology 12
 besides phospholipids, cell membranes also contain protiens

transport protiens

enzymes

recognitoin protiens

adhesion protiens

receptor proteiens

two major categories of cells

prokaryotic cells

bacteria, archara

eukaryotic cells

plants, animals, fungi, protists

Biology 13
 anatomy of a bacterium
bacteria are prokaryotic. DNA is free in the cytoplasm

the anatomy of the animal cell

Biology 14
 animal cells are eukaryotic. they have membrane bound organelles\

anatomy of a plant cell

plant cells are also eukaryotic, but notice the cell wall and chloroplasts

Biology 15
 cell surfaces
plant cells have cell walls, which help protect the cells, maintain their shape, and keep
the cells from absorbing too much water

Biology 16
 eukaryotic cells

protists, fungi, plants, and animals

compartmentalized and contain organelles

categories of organelles

endomembrane system

energy converters

cytoskeleton

the endomembrane system

→manufacturing and distriburing cellular products
→→the endomembrane system consists of the nuclear envolope, endoplasmic reticulum
(ribosomes), golgi apparatus, lysosomes, vacuoles, and cell membrane

Biology 17
 lysosomes are part of the clean-up crew

vacuoles are membranous sacs

contractile vacuoles

central vacuoles

Biology 18
 energy converters: mitochondria
many of the processes discussed so far require energy. where does the energy come
from?
the mitochondria are the cites of cellular respiration, which involves the produciton of
ATP from food molecules

energy converters: chloroplast

eukaryotes that carry out photosynthesis have chloroplasts, organelles that use sunlight
to produce food for the cell

Biology 19
 the endosymbiotic theory

Biology 20
 cytoskeleton

network of protein tracks and tubules

functions

structural support

aids in cell division

organelle transport

cell movement

Biology 21
 motor proteins move vesicles

cilia and flagella

Biology 22
 cilia and flagella are motile appendages

maintaining cell shape

not all cells are equal

Biology 23
 worksheets kinda

#1

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 #2

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 chapter 4

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